[tor-bugs] #13912 [Core Tor/Tor]: Key Security: Zeroing Buffers Is Insufficient (AES-NI leaves keys in SSE registers)

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#13912: Key Security: Zeroing Buffers Is Insufficient (AES-NI leaves keys in SSE
registers)
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 Reporter:  teor                                 |          Owner:
     Type:  defect                               |         Status:  new
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  unspecified
Component:  Core Tor/Tor                         |        Version:  Tor:
                                                 |  0.2.6.1-alpha
 Severity:  Normal                               |     Resolution:
 Keywords:  security registers aesni memwipe     |  Actual Points:
  tor-relay                                      |
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
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Comment (by yawning):

 Replying to [comment:11 cypherpunks]:
 > What about ROP gadgets that do not provide turing complete behavior (so
 no "arbitrary" code execution), but still expose the sensitive registers?

 I think you've likewise effective lost at that point.  Patch OpenSSL's
 assembly in strategic locations if you actually care about this, though
 there's a a lot of other places in the code that don't scrub "sensitive"
 keying information so IMO this is a lost cause.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/13912#comment:12>
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